Method and Apparatus for Treating of Raw Biomaterial

ABSTRACT

The object of the invention is a method and an apparatus relating to the dry distillation of raw biomaterial and to the recovery of different compounds as a continuous process. In the method according to the invention, raw material is dry distilled in at least two separate dry distillation zones maintained in pressures and/or temperatures different from each other. A multi-layer dry distiller pertaining to the apparatus according to the invention consists of at least two separate dry distillation tubes maintained in different pressures and/or temperatures from each other to implement different dry distillation zones.

The method and apparatus according to the invention relate to the treating of raw biomaterial and particularly to the dry distillation of raw biomaterial and the recovery of different compounds as a continuous process.

In this context, dry distillation refers to the thermochemical i.e. heat-induced conversion of raw material into separate states, into solids, liquids and gases.

It is previously known to continuously dry distil powdery raw biomaterial in tubular retorts where raw material is conveyed in the tube by a screw, dried, heated, carbonised and cooled. Dry distillation products are gases, liquids, carbon and ashes.

During dry distillation, plenty of different compounds are gasified of the raw material depending on prevailing conditions. Gasifiable materials and compounds react partially mutually e.g. from the effect of temperature, pressure and various catalysts forming several new compounds.

Gasifiable materials are e.g. alkanes, alkenes, alkyls, ketones, phenols, sterols, terpenes, terpenoids, alcohols, acids and ethers. In the previously known continuous dry distillation methods of raw biomaterial, gasifiable compounds are mixed together forming complex compounds and their mixtures from the above materials.

The dry distillation of powdery raw biomaterial is known e.g. from patent specifications JP57096084, CN201339016, WO2005/049530, WO96/32163 and U.S. Pat. No. 2,973,306.

The object of the invention is to introduce a method and an apparatus implementing the method, which dry, distil raw biomaterial as a continuous process efficiently and cost-effectively.

The method and apparatus according to the invention are characterised by what is stated in the characterising part of claim 1 and the characterising part of the first apparatus claim.

According to the invention, raw material is dry distilled in at least two separate dry distillation zones maintained in pressures and/or temperatures different from each other. Then, the efficiency of dry distillation increases, as in the separate dry distillation zone are gasified only materials and compounds according to the conditions prevailing in it which are not allowed to mix with gasifiable materials and compounds in other dry distillation zones.

In an advantageous embodiment of the invention, gasifiable materials and compounds from dry distillation zones being in different conditions are recovered such that they cannot mix with gasifiable materials and compounds in other dry distillation zones. When the materials and compounds gasifiable in different conditions cannot mix with each other, their further processing, such as e.g. separation by the column method, is easier and more cost-effective. The method enables the more detailed separation of gasifiable components of economic value.

In an advantageous further embodiment of the invention, powdery raw biomaterial is dry distilled. The method and apparatus are also suitable for the dry distillation of other raw biomaterials.

In an advantageous further embodiment of the invention, the dry distillation of raw biomaterial takes place in overlapping dry distillation zones. Then, raw material is induced to flow from one dry distillation zone to another from the top downwards and heat is conveyed to heat the zones from the bottom upwards such that the bottom has the hottest conditions and the top the coolest.

The method repeats a dry distillation step, when raw material is not induced to flow, and a conveyance step, when raw material is induced to flow in dry distillation zones.

In the conveyance step of the method, raw biomaterial is induced to flow in the dry distillation zone by pushing it periodically first from the starting side to the other side in order for the raw material to compress due to pressing force into compact and better-controllable dry distillation raw material. Then, the raw material is compressed in the dry distillation zone into compact and well heat-conductive mass by a piston, which also pushes the raw material in the dry distillation zone forward in the conveyance step of raw material and compresses the dry distillation zone during the dry distillation step. After this, raw material is induced to flow in the following dry distillation zone, whereby the conveyance direction of the raw material changes back towards the starting side. The raw material is thus conveyed back and forth in the horizontal direction and from the top downwards in the vertical direction such that the following dry distillation zone has hotter conditions than the previous one.

According to the invention, a multi-layer dry distiller pertaining to the apparatus consists of at least two separate dry distillation tubes maintained in pressures and/or temperatures different from each other to implement different dry distillation zones.

A dry distillation apparatus implementing the method advantageously consists of wide, long and low shaped dry distillation tubes, which are set overlapping and antiparallel. Raw material is induced to flow by pistons and gasifiable materials and compounds are recovered through valves. The apparatus is heated by means of heat exchangers from the bottom upwards.

Other advantageous embodiments are presented in the other dependent claims.

Next, an example will be described of a multi-layer dry distiller 1 implementing the method and of the method enabled by it with reference to the enclosed drawing. The invention is not, however, limited to this embodiment. In the drawing,

FIG. 1 shows an oblique top view of a dry distillation tube,

FIG. 2 shows a schematic and cutaway view of a dry distillation tube according to the invention and

FIG. 3 shows a schematic and cutaway view of an embodiment of an apparatus according to the invention.

The multi-layer dry distiller 1 according to FIG. 3 consists of overlapping and antiparallel planar, mainly rectangular dry distillation tubes 3 for implementing different dry distillation zones 2. The dry distillation tubes are isolated from each other. According to FIGS. 1 and 2, the dry distillation tube 3 and the dry distillation zone 2 within it are planar i.e. long, wide and low for having a large heating area and quick heat transfer.

At one end of the dry distillation tube 3, there is a piston 4 for compressing the raw material, for inducing it to flow forward and for isolating different conditions and, at the same end, above the tube, there is a feed opening 7 for receiving the raw material. At the opposite end of the dry distillation tube 3, there is a valve 5 for recovering gasifiable materials and compounds and, below the tube, an outlet opening 8 for removing the raw material. Below the dry distillation tube 3 is connected a heat exchanger 6 for heating the dry distillation tube 3.

According to FIG. 3, the overlapping dry distillation tubes are located opposedly in relation to the flow direction of raw material such that the outlet opening of the upper tube and the feed opening of the lower tube are facing each other. In the dry distillation apparatus, the different conditions of the dry distillation zones are maintained by means of heat supply required by the conditions through heat exchangers and the different dry distillation conditions are isolated from each other by means of pistons and valves, which also maintain the desired pressure.

In the example shown in FIG. 3, the multi-layer dry distiller 1 consists of four overlapping dry distillation zones 2. The dry distillation zone 2 is implemented by the dry distillation tube 3, having the width of 2,000 mm, the length of 1,500 mm and the height of 40 mm in this embodiment.

In the method example, powdery raw biomaterial is fed to the dry distillation zone 2 from the feed opening 7. Raw material is induced to flow in the dry distillation zone 2 of the dry distillation tube 3 by the piston 4 and the heating required by the dry distillation conditions is implemented through the heat exchanger 6. The gasifiable materials and compounds are recovered through the valve 5 and ungasifiable materials are induced to flow by means of the piston 4 to the outlet opening 8.

All dry distillation zones 2 of the multi-layer dry distiller 1 follow the same process flow of the method example. In the multi-layer dry distiller 1, raw material is induced to flow from the top downwards and heat is transferred from the bottom upwards. Unprocessed raw material is fed to the topmost layer and processed ungasifiable material is recovered from the bottommost layer.

The dry distillation apparatus utilises prior-art techniques to implement the method, such as e.g. sensors for measuring and controlling the conditions and for controlling the feed of raw material. Previously known techniques are also employed e.g. for separating and preserving dry distillation products and for heating the dry distillation apparatus.

It is possible to attach the multi-layer dry distiller with prior-art devices to implement the method, such as devices for maintaining the conditions, for inducing raw material and processed products to flow and for controlling the system. Furthermore, it is possible to attach the multi-layer dry distiller with prior-art devices for further processing dry distillation products, such as a fractional distillation device for separating different distillation results according to condensation points, a cracking device for cracking complex compounds and devices for combining and preserving different materials.

The invention is not limited to the advantageous embodiment described. The method and apparatus can also be employed in processing other raw biomaterials than powdery raw biomaterials. 

1. A method for the treating of raw biomaterial and particularly for the continuous dry distillation of raw biomaterial, characterised by dry distilling raw material in at least two separate dry distillation zones (2) maintained in pressures and/or temperatures different from each other.
 2. A method according to claim 1, characterised by recovering gasifiable materials and compounds from the dry distillation zones (2) being in different conditions such that they cannot mix with gasifiable materials and compounds in other dry distillation zones (2).
 3. A method according to claim 1 or 2, characterised by, in the method, dry distilling powdery raw biomaterial.
 4. A method according to any one of claims 1-3, characterised by dry distilling raw biomaterial in overlapping and antiparallel dry distillation zones (2).
 5. A method according to claim 1, characterised by compressing raw material in the dry distillation zone (2) into a compact and well heat-conductive mass by a piston (4) which also pushes the raw material in the dry distillation zone (2) forward in the conveyance step of raw material and compresses the dry distillation zone (2) during the dry distillation step.
 6. A method according to claim 1, characterised by inducing raw material to flow between the overlapping dry distillation zones (2) in the horizontal direction back and forth and in the vertical direction from the top downwards such that the following dry distillation zone (2) always has hotter conditions than the previous one.
 7. An apparatus implementing the method according to claim 1, characterised in that a multi-layer dry distiller (1) pertaining to the apparatus consists of at least two separate dry distillation tubes (3) maintained in pressures and/or temperatures different from each other for implementing different dry distillation zones (2).
 8. An apparatus according to claim 7, characterised in that the dry distillation tubes are overlapping and antiparallel.
 9. An apparatus according to claim 7 or 8, characterised in that one end of the dry distillation tube (3) includes a piston (4) for compacting raw material and inducing it to flow and for isolating different conditions and a feed opening (7) for receiving raw material, the opposite end of the dry distillation tube (3) includes a valve (5) for recovering gasifiable materials and compounds and an outlet opening (8) for removing the raw material, and that below the dry distillation tube (3) is attached a heat exchanger (6) for heating the dry distillation tube (3). 